Perhaps it's also worth talking about imageboards.
Imageboards also suffer from newcomers asking the same questions, though this is mitigated by third party archive sites and encouragement to use them, to the point in which a common reply to a newbie question will be "search the archive". There are only about 15 pages of threads (with about 10 threads on each page) active at a time, which is significantly less than on a subreddit. You cannot reply to deleted threads, but individual threads can reach around 350 replies if they're baity/good.
Imageboards have no notion of karma, except social. You usually (save for boards with in-thread IDs) can be an expert on one topic in a thread, then ask a newbie question later on, letting you also play devil's advocate. This is because you can be anonymous. But if you want to attach your name to your posts, you can do so securely using a code which nobody can replicate unless they also know the password to generate it that you know (a tripcode). People who use tripcodes are frequently derided (such as by being called "tripfags").
Imageboards are relatively easy to use. You post a thread using a form at the top of each board page, and reply to a thread using the same form at the top of the thread page, which is accessed by clicking "Reply" displayed next to an individual thread on the board pages.
Imageboards usually host multiple boards. 4chan for example has a board for most topics people are interested in, from anime, technology and toys to papercraft, transportation and the paranormal. Within these boards, it is common to have "general" threads in which they act like miniature boards, threads created for just one topic, however they are not moderated, as they are set up by regualar users, so they can go off-topic. For example, /g/ (the Tech board) has a frequent general thread called "/tpg/ - Thinkpad general" in which people can talk about IBM Thinkpad laptops. Multiple people can create topical threads with the same subject line.
Other imageboards let you create your own board, the most prominent example of which is 8chan; by creating a board you become its moderator and administrator, subject to the global rules of the website, of course.
Imageboards, like Reddit, have a feedback loop in which commenting in a thread will bump it to the top of the board, so people viewing the first page of the board will see that thread. Unpopular threads tend to fall in ranking until they are eventually bumped off the board by a new thread. To avoid participating in the feedback loop, you can "sage" a thread, which is to post in it, but not bump it to the top.
But most importantly I will reiterate - imageboards are anonymous, there are no accounts, and there is no barrier to participation except maybe feeling bad because you haven't lurked enough.
I'm not the first to talk about the virtues of imageboards over traditional forum stoftware (phpBB, Reddit, etc.): https://wakaba.c3.cx/shii/shiichan
And this is of course ignoring that you can use an imageboard to host a personal blog, by only allowing a pre-defined administrator tripcode to post, and to set new replies to not bump threads. It's a real shame the flourish of earlier imageboards died, as they were often home to quality discussion.